If a, b, and c are consecutive integers such that a < b < c, and a + b + c = 24, what is the value of a * c?
Correct: C
Since a, b, and c are consecutive integers, we can write b = a + 1 and c = a + 2. Then a + (a + 1) + (a + 2) = 24 => 3a + 3 = 24 => 3a = 21 => a = 7. Then c = a + 2 = 7 + 2 = 9. Therefore, a * c = 7 * 9 = 63.